BirdAnalyst
Species · North Dakota · BBS 2025 Release · 1966–2024

Great Horned Owl Population Trend in North Dakota

All statesGeneralists

Great Horned Owl in North Dakota has held roughly steady: down 7% on the route-weighted index since 1970.

-7%Since 1970TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
49Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
56YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Great Horned Owl Trends in North DakotaNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Great Horned Owl in North Dakota. See the full index history below.

Great Horned Owl Population Forecast in North Dakota

If the recent trend holds, Great Horned Owl in North Dakota is projected to rise about 133% by 2029 — from 0.18 in 2024 to a central estimate of 0.43 (95% range 0.07–0.80). A 5-year backtest shows a typical error of ±189.3%, with 80% of held-out values landing inside the 95% band.

+133%Change by 2029TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
0.43Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.07–0.8095% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±189.3%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Great Horned Owl in North Dakota is projected to rise about 133% by 2029 — from 0.18 in 2024 to a central estimate of 0.43 (95% range 0.07–0.80). A 5-year backtest shows a typical error of ±189.3%, with 80% of held-out values landing inside the 95% band.19682029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
20250.420.060.79
20260.420.060.79
20270.430.060.79
20280.430.070.79
20290.430.070.80

Great Horned Owl Survey Routes in North Dakota

Routes recording Great Horned Owl in North Dakota.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
Horsehead Lk320181988
Forman220211972
Sydney219801968
Emerado220161979
Cooperstown220211970
Buchanan220221968
Dickinson220241972
Tobacco219961968
Denbigh220221971
Gorham220171988
Wild Rose220191982
Powers Lake220121985
Danzig 2220212021
Walcott120151986
Edgeley120241983
Lake George120181968
Danzig120101982
Kempton119971979
Wimbledon120191990
Bowesmont119811981
Nash120131983
Lakota120061972
Webster120171993
Rolla120211973
Niles120181989

Great Horned Owl Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.